Control of a single electrochromic window in isolation is relatively much simpler than control of electrochromic windows for a large installation such as an entire building. Also, repair or replacement of a single electrochromic window in isolation is simpler and less expensive than replacement or repair of an electrochromic window that has been installed in a building, especially a large commercial building in an urban area, where rental of a crane and street closure could be required for removal of the window. Regardless of location, it is undesirable to have an electrochromic window fail. In addition, features leading to user satisfaction may be unavailable in a simpler controller for electrochromic windows. It is within this context that the embodiments arise.